A generic exhaust-driven turbocharger is known for example from WO 2004/022926 A1, in which a housing of the exhaust-driven turbocharger and its adjustable, variable turbine and/or compressor geometry are decoupled mechanically and/or thermally from each other. Thermally induced expansions in particular are intended to be better accommodated by this. A cartridge is screw-fastened to a bearing housing and has an axial gap towards the turbine housing for thermal decoupling.
Generally, all the components of an exhaust-driven turbocharger are usually subject to severe temperature fluctuations during operation and, owing to the use of different materials and different geometries, expansions of different severities, so that these components, as long as they are connected in a fixed manner to each other, can be under great thermal stresses, which in the least favourable case can lead to failure of the actual function or to destruction of the component. The guide vane cage is there for the purpose of forming as small and homogenous a gap as possible to a turbine wheel of the charging device, wherein the gap must be large enough so that wobbling movements of a rotor, which is composed of the turbine wheel and a shaft, as well as manufacturing and assembly tolerances are possible without contact between the turbine wheel and the guide vane cage occurring.